The Gradient of Exciting Radiation within a Sample Affects the Relative Height of Steps in the Fast Chlorophyll a Fluorescence Rise

P. Sušila, D. Lazár, P. Ilík, P. Tomek, J. Nauš

Photosynthetica 2004, 42(2):161-172 | DOI: 10.1023/B:PHOT.0000040586.39903.db

Measurement of the chlorophyll (Chl) a fluorescence rise (FR) under higher exciting irradiance (EI), the O-J-I-P transient, or under lower irradiance, the O-I-P transient, is a routinely used method to access photosystem 2 function in thylakoid membranes of chloroplasts. Our measurements with a suspension of pea thylakoid membranes showed that the relative heights of the J and I steps in the FR depended not only on EI but also on the concentration and thickness of the sample. We explain this effect as a consequence of the gradient of EI within the sample. We tested this suggestion by theoretical simulations of the FR based on the model that...

Changes in Morphology, Anatomy, and Photosynthetic Capacity of Needles of Japanese Larch (Larix kaempferi) Seedlings Grown in High CO₂ Concentrations

N. Eguchi, E. Fukatsu, R. Funada, H. Tobita, M. Kitao, Y. Maruyama, T. Koike

Photosynthetica 2004, 42(2):173-178 | DOI: 10.1023/B:PHOT.0000040587.99518.a8

Photosynthetic traits of two-year-old Japanese larch seedlings (Larix kaempferi Carr.) grown at elevated CO₂ concentrations were studied in relation to structural changes in the needles. Seedlings were grown at two CO₂ concentrations, 360 (AC) and 720 (EC) μmol mol^-1 at high and low nutrient supply rates, high N (HN) and low N (LN). The photosynthetic capacity fell significantly in EC+LN, but increased significantly in EC+HN. Since the mesophyll surface area exposed to intercellular space per unit leaf area (A^mes/A) is correlated with the photosynthetic rate, we measured A^mes/A for larch...

Low Temperature Tolerance of Tobacco Plants Transformed to Accumulate Proline, Fructans, or Glycine Betaine. Variable Chlorophyll Fluorescence Evidence

D. Parvanova, A. Popova, I. Zaharieva, P. Lambrev, T. Konstantinova, S. Taneva, A. Atanassov, V. Goltsev, D. Djilianov

Photosynthetica 2004, 42(2):179-185 | DOI: 10.1023/B:PHOT.0000040588.31318.0f

Tobacco (Nicotiana tabacum L.) has been transformed to accumulate different compatible solutes (proline, fructans, or glycine betaine) in order to improve its tolerance to abiotic stress. Photosynthetic activity of wild Type (wt) and transformed tobacco plants before and after freezing stress was studied by measuring chlorophyll (Chl) fluorescence. The JIP test of Chl fluorescence induction was used to analyze in details the functional activity of photosystem 2. No significant differences were found among wild Type and transgenic plants after 12 h of freezing. Both plant Types maintained the same values of the measured parameters [F_V/F_M,...

Britton, G., Liaaen-Jensen, S., Pfander, H. (ed.): Carotenoids. Handbook

Z. Šesták

Photosynthetica 2004, 42(2):186 | DOI: 10.1023/B:PHOT.0000040641.40049.19

Effect of a Short Photoinhibition Stress on Photosynthesis, Chlorophyll a Fluorescence, and Pigment Contents of Different Maize Cultivars. Can a Rapid and Objective Stress Indicator be Found?

P. Lootens, J. Van Waes, L. Carlier

Photosynthetica 2004, 42(2):187-192 | DOI: 10.1023/B:PHOT.0000040589.09614.a0

The effect of a short cold stress in combination with photoinhibition stress, similar to a low temperature and a high irradiance situation during early morning in the spring time, was examined on four maize cultivars common for Belgium, that differ in early vigour. After 1 h of 2 °C and 500 μmol(photon) m^-2 s^-1, quantum efficiency and maximum photosynthesis rate at saturating irradiance decreased on average by 11 and 8 %, respectively. For one cultivar, Magister, the decrease was the largest: by 23 and 10 %, respectively. For this cultivar it was combined with a decrease of the water vapour conductance after the stress. The...

Interaction of Photosystem 2-LHC2 Supercomplexes in Adjacent Layers of Stacked Chloroplast Thylakoid Membranes

L. Bumba, M. Hušák, F. Vácha

Photosynthetica 2004, 42(2):193-199 | DOI: 10.1023/B:PHOT.0000040590.10919.02

Two Types of photosystem 2-light-harvesting complex 2 (PS2-LHC2) supercomplexes with similar pigment and protein composition were isolated directly from thylakoid membranes by sucrose density gradient centrifugation. Electron microscopy and single particle image analysis revealed the first Type as single unpaired PS2-LHC2 supercomplexes, whereas the second Type was characterized as pairs of two PS2-LHC2 supercomplexes attached together by their stromal sides. Unstacking of thylakoid membranes resulted in a spontaneous disintegration of the paired supercomplexes into single unpaired particles. A model of the organisation of the pigment-protein complexes...

Johnson, T.: Herbage. 3^rd Ed.

Z. Šesták

Photosynthetica 2004, 42(2):200 | DOI: 10.1023/B:PHOT.0000040643.12399.87

Influence of Temperature on the Effects of Artificially Enhanced UV-B Radiation on Aquatic Bryophytes Under Laboratory Conditions

E. Núñez-Olivera, J. Martínez-Abaigar, R. Tomás, N. Beaucourt, M. Arróniz-Crespo

Photosynthetica 2004, 42(2):201-212 | DOI: 10.1023/B:PHOT.0000040591.74037.f1

We examined, under laboratory conditions, the influence of temperature (2 °C vs. 10 °C) on the physiological responses of two aquatic bryophytes from a mountain stream to artificially enhanced UV-B radiation for 82 d. These organisms may be exposed naturally to relatively low temperatures and high levels of UV-B radiation, and this combination is believed to increase the adverse effects of UV-B radiation. In the moss Fontinalis antipyretica, UV-B-treated samples showed severe physiological damages, including significant decreases in chlorophyll (Chl) and carotenoid (Car) contents, Chl a/b and Chl/phaeopigment ratios, Chl a...

Photosynthetic Responses of Four Hosta Cultivars to Shade Treatments

J.Z. Zhang, L. Shi, A.P. Shi, Q.X. Zhang

Photosynthetica 2004, 42(2):213-218 | DOI: 10.1023/B:PHOT.0000040592.10133.ee

The effects of shade on the gas exchange of four Hosta cultivars were determined under differing irradiances (5, 30, 50, and 100 % of full irradiance) within pots. Irradiance saturation ranged between 400-800 μmol m^-2 s^-1 among the four cultivars, of which H. sieboldiana cv. Elegans and H. plantagenea cv. Aphrodite exerted the lowest saturation and compensation irradiances. The maximal photosynthetic rate (P_max) was significantly higher in shade than in full irradiance in Elegans and Aphrodite, and was at maximum in seedlings grown in 30 % of full irradiance. The best shade treatment for...

Photosynthetic Pathways and Life Form Types for Native Plant Species from Hulunbeier Rangelands, Inner Mongolia, North China

R.Z. Wang

Photosynthetica 2004, 42(2):219-227 | DOI: 10.1023/B:PHOT.0000040593.18169.18

Photosynthetic pathway Types (C₃, C₄, and CAM) and life forms of native species from Hulunbeier rangelands, north China were studied. Of the total 258 species, 216 species in 132 genera and 42 families had C₃ photosynthetic pathway, including dominant herbs, e.g. Stipa baicalensis Roshev. and Leymus chinensis (Trin.) Tzvel., Filifolium sibiricum Kitam. and Arudinella hirta (Thunb.) Koidz. 38 species in 28 genera and 10 families were found with C₄ photosynthesis, and 4 species in 2 genera and 1 family had CAM photosynthetic pathway. The occurrence of C₄ species was common...

Green, B.R., Parson, W.W. (ed.): Light-Harvesting Antennas in Photosynthesis

Z. Šesták

Photosynthetica 2004, 42(2):228 | DOI: 10.1023/B:PHOT.0000040642.24968.e1

Exceptional Photosynthetic Performance of Capparis spinosa L. Under Adverse Conditions of Mediterranean summer

E. Levizou, P. Drilias, A. Kyparissis

Photosynthetica 2004, 42(2):229-235 | DOI: 10.1023/B:PHOT.0000040594.85407.f4

Diurnal and seasonal fluctuations in water potential (Ψ), stomatal conductance (g_s), transpiration rate (E), and net photosynthetic rate (P_N) were monitored in Capparis spinosa L., a Mediterranean plant growing during summer, i.e. at the period considered the most stressful for local plant life. In spite of the complete absence of rain, Ψ exhibited a modest drop at midday (-2.7 MPa), but was fully recovered overnight, indicating sufficient access to water sources. The stomata remained open throughout the day and season and the high E resulted in leaf temperatures up to 3.9 °C below...

Taihangia rupestris, a Rare Herb Dwelling Cliff Faces: Responses to Irradiance

Min Tang, Fei-Hai Yu, Shu-Min Zhang, Shu-Li Niu, Xiao-Bai Jin

Photosynthetica 2004, 42(2):237-242 | DOI: 10.1023/B:PHOT.0000040595.23045.bf

We studied the responses of gas exchange, leaf morphology, and growth to irradiance in Taihangia rupestris, a naturally rare herb inhabiting only vertical cliff faces. In low irradiance (LI, 10 % of full sun) T. rupestris had lower net photosynthetic rate (P_N) and produced much less leaves, total leaf area, and biomass than in high (HI, full sun) or medium irradiance (MI, 50 % of full sun). P_N of T. rupestris was higher in HI than in MI on August 8, but lower in HI than in MI on September 22. T. rupestris had shorter petioles and lower leaf area ratio, and produced more but smaller and...

Traits of Chlorophyll Fluorescence in 99 Plant Species from the Sparse-Elm Grassland in Hunshandak Sandland

Yong-Geng Li, Ling-Hao Li, Gao-Ming Jiang, Shu-Li Niu, Mei-Zhen Liu, Lei-Ming Gao, Yu Peng, Chuang-Dao Jiang

Photosynthetica 2004, 42(2):243-249 | DOI: 10.1023/B:PHOT.0000040596.39460.6f

Sparse-elm grassland is the remarkable landscape of Hunshandak Sandland in Inner Mongolia Autonomic Region of China. Maximum quantum efficiency (F_v/F_m) of 99 native plant species (85 grasses, 11 shrubs, and 3 trees) of different plant functional Types (PFTs) distributed in fixed sand dune, lowland, and wetland was investigated. Deep-rooted plant species (tree, shrub, and perennial grass) had higher F_v/F_m values than the shallow-rooted species (annual grasses), suggesting that soil drought is the major environmental stress. Annual C₄ grasses had higher F_v/F_m values than annual...

Influence of Potassium Nutrition on Gas Exchange Characteristics and Water Relations in Cotton (Gossypium hirsutum L.)

H. Pervez, M. Ashraf, M.I. Makhdum

Photosynthetica 2004, 42(2):251-255 | DOI: 10.1023/B:PHOT.0000040597.62743.5b

The effects of potassium nutrition [0, 6.25, 12.50, 25.00 g(K) m^-2 of K₂SO₄ or KCl] on gas exchange characteristics and water relations in four cultivars (CIM-448, CIM-1100, Karishma, S-12) of cotton were assessed under an arid environment. Net photosynthetic rate (P_N) and transpiration rate (E) increased with increased K supply. The leaf pressure potential (Ψ_p) increased significantly by the addition of 25.00 g(K) m^-2 compared to zero K level. The water use efficiency (P_N/E) was improved by 24.6 % under the highest K dose compared to zero K....

Factors Limiting Photosynthetic Recovery in Sweet Pepper Leaves After Short-Term Chilling Stress Under Low Irradiance

X. G. Li, X. M. Wang, Q. W. Meng, Q. Zou

Photosynthetica 2004, 42(2):257-262 | DOI: 10.1023/B:PHOT.0000040598.48732.af

The effects of chilling treatment (4 °C) under low irradiance, LI (100 μmol m^-2 s^-1) and in the dark on subsequent recovery of photosynthesis in chilling-sensitive sweet pepper leaves were investigated by comparing the ratio of quantum yields of photosystem (PS) 2 and CO₂ assimilation, Φ_PS2/Φ_CO2, measured in normal air (21 % O₂, NA) and low O₂-air (2% O₂, LOA), and by analyzing chlorophyll (Chl) a fluorescence parameters. Chilling treatment in the dark had little effect on F_v/F_m and Φ_PS2/Φ_CO2,...

High Irradiance Induced Changes of Photosystem 2 in Young and Mature Needles of Cypress (Cupressus sempervirens L.)

N. La Porta, M. Bertamini, N. Nedunchezhian, K. Muthuchelian

Photosynthetica 2004, 42(2):263-271 | DOI: 10.1023/B:PHOT.0000040599.63773.ef

Photoinhibition of photosynthesis was studied in young and mature detached sun needles of cypress under high irradiance (HI) of about 1 900 μmol m^-2 s^-1. The degree of photoinhibition was determined by means of the ratio of variable to maximum chlorophyll (Chl) fluorescence (F_v/F_m) and electron transport measurements. Compared with the mature needles, the young needles, containing about half the amount of Chl a+b per unit area, exhibited a higher proportion of total carotenoids (Car) as xanthophyll cycle pigments and had an increased ratio of Car/Chl a+b. The potential efficiency of photosystem...

Photoacclimation of Dunaliella tertiolecta (Chlorophyceae) Under Fluctuating Irradiance

H. Havelková-Doušová, O. Prášil, M.J. Behrenfeld

Photosynthetica 2004, 42(2):273-281 | DOI: 10.1023/B:PHOT.0000040600.04502.32

We investigated photoacclimation of Dunaliella tertiolecta (Butcher) in irradiance (I) regimes simulating mixed layer conditions of turbid estuarine waters or lakes. D. tertiolecta was exposed to a range of fixed I regimes to establish baseline physiology-I relationships that were compared with subsequent photoacclimation to a simulated mixed layer. Measured indices of photoacclimation included cellular pigmentation, chlorophyll variable fluorescence, and effective photosystem 2 antenna size. While D. tertiolecta grown under fluctuating I maintained division rates comparable to cells grown at high I,...

Regulation of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase in vivo: Control by High CO₂ Concentration

J. Viil, H. Ivanova, T. Pärnik, E. Pärsim

Photosynthetica 2004, 42(2):283-290 | DOI: 10.1023/B:PHOT.0000040601.48732.fa

High CO₂ concentrations (HC) in air induce partial deactivation of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO, EC 4.1.1.39). Under saturating irradiance, increase in [CO₂] to 1 200 cm³ m^-3 reduces the concentration of operating carboxylation centres by 20-30 %. At a further increase in [CO₂], the activity remained on the same level. Under limiting irradiance, the lowest activity was reached at 600 cm³(CO₂) m^-3. The presence of oxygen diminished deactivation, but O₂ failed to stimulate reactivation under high CO₂. Conditions that...

Photosynthetic Responses of Tropical Trees to Short-Term Exposure to Ozone

R.M. Moraes, C.M. Furlan, P. Bulbovas, M. Domingos, S.T. Meirelles, A. Salatino, W.B.C. Delitti, M.J. Sanz

Photosynthetica 2004, 42(2):291-293 | DOI: 10.1023/B:PHOT.0000040602.20847.c6

Saplings of the tropical trees Tibouchina pulchra (Cham.) Cogn., Caesalpinia echinata Lam., and Psidium guajava L. cv. Paluma were exposed in open-top chambers with charcoal filtered air and measurements of gas exchange and chlorophyll fluorescence were made before (t₁) and after exposure to non-filtered air plus O₃ (t₂), simulating 6-h peaks of O₃ similar to those observed in São Paulo city (SE Brazil, reaching an AOT40 of 641 nmol mol^-1). After the fumigation, the net photosynthetic rate, stomatal conductance, transpiration rate, and F_v/F_m...

Total Carotenoid Amount in Crude Twig Extracts May Be Overestimated Due to Interference by High Contents of Co-Extracted Phenolics

E. Levizou, Y. Petropoulou, Y. Manetas

Photosynthetica 2004, 42(2):295-297 | DOI: 10.1023/B:PHOT.0000040603.14529.28

Total carotenoids assessed spectrophotometrically in crude extracts may be considerably overestimated when high contents of phenolic compounds are co-extracted. In this case, the absorbance tails of phenolics extend well into the blue part of the spectrum, interfering with carotenoid estimation. Extracts of phenolic-rich organs, with a low ratio of photosynthetic to heterotrophic and/or supportive cells (for example, stems or twigs) are vulnerable to such pitfalls and may need chromatographic separation of carotenoids.

Irradiation-Regulated Differential Accumulation of Chloroplast-Encoded Transcripts in Mature Leaves of Populus deltoides

S. Srivastava, P.K. Trivedi, P. Nath

Photosynthetica 2004, 42(2):299-301 | DOI: 10.1023/B:PHOT.0000040604.92482.eb

Steady state transcript levels of psbA, rbcL, atpB, and psbN genes accumulated differentially in mature leaves of a field-grown tree Populus deltoides during natural diurnal cycle and in dark adaptation followed by irradiation. The rbcL transcript accumulated independent of irradiation under diurnal conditions, which demonstrated a correlation with the phenomenon of midday depression in photosynthesis. The psbA and atpB transcripts accumulated more in dark whereas psbN accumulated more in light. Diurnal rhythm of gene expression in mature chloroplasts was independent of development related changes.

Differences in the Activation State of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase in Barley, Pea, and Wheat at Two Altitudes

Narinder Kumar, Sanjay Kumar, Paramvir Singh Ahuja

Photosynthetica 2004, 42(2):303-305 | DOI: 10.1023/B:PHOT.0000040605.30120.d3

Activation state of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) is an important parameter determining the rate of net photosynthesis (P_N) in situ for which no information is available with reference to altitude. We analyzed activation state along with P_N in three plant species and their cultivars grown at low (LA, 1 300 m) and high (HA, 4 200 m) altitudes. No significant change in P_N and the initial activity of RuBPCO was obtained with reference to altitude. However, activation state of RuBPCO was reduced significantly in the HA plants as compared to the LA ones. Hence low partial...

Responses of the Fructose-1,6-bisphosphatase and Glutamate Dehydrogenase Activities of Alfalfa to Boron, Gypsum, and Limestone Amendments of Soil

G.O. Osuji, V.A. Haby, D.J. Chessman, A.T. Leonard

Photosynthetica 2004, 42(2):307-312 | DOI: 10.1023/B:PHOT.0000040606.16109.61

Plants cultivated on acid soils that contain toxic levels of Al³⁺ usually produce low yields. A multi-factorial treatment of gypsum (G), boron (B), and limestone (Lm) was applied to such soil in order to determine the biochemical basis of the best management plan for ameliorating the soil acidity for sustainable growth of alfalfa. The alfalfa shoots were subjected to analysis for hexose, protein, nucleotide, and chlorophyll (Chl) contents, fructose 1,6-bisphosphatase (FBPase) activity, and the RNA synthetic activity of glutamate dehydrogenase (GDH). Hexose and protein contents of control alfalfa without B and G, but with Lm (672 g m^-2)...

¹⁴CO₂ Assimilation and ¹⁴C-photosynthate Translocation in Different Leaves of Sunflower

Desiraju Subrahmanyam, V.S. Rathore

Photosynthetica 2004, 42(2):313-316 | DOI: 10.1023/B:PHOT.0000040607.67963.38

Chlorophyll and nitrogen contents were highest in leaves of middle position, similarly as photosynthetic efficiency represented by ¹⁴C fixation (maxima in leaf 5 from the top). All the leaves lost ¹⁴C after 2 weeks of ¹⁴CO₂ exposure. However, the reduction in radioactivity was less in young upper leaves than in the mature lower leaves. Leaves exported ¹⁴C-photosynthates to stem both above and below the exposed leaf. Very little radioactivity was recovered from the seeds of plants in which only first or second leaves were exposed to ¹⁴CO₂ implying thereby that the carbon contribution...

Effect of Heat Stress During Grain Filling on Phosphoenolpyruvate Carboxylase and Ribulose-1,5-bisphosphate Carboxylase/Oxygenase Activities of Various Green Organs in Winter Wheat

X. L. Xu, Y. H. Zhang, Z. M. Wang

Photosynthetica 2004, 42(2):317-320 | DOI: 10.1023/B:PHOT.0000040608.97976.a3

In two winter wheat (Triticum aestivum L.) cultivars differing in their response to high temperature, JD8 (tolerant) and J411 (sensitive) we studied the effect of heat stress on the activities of phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase (RuBPC) in green organs during grain-filling. There were significantly higher PEPC activities and lower RuBPC activities in each of the non-leaf organs (awn, glume, lemma, peduncle, and sheath) than in the flag leaf blade. Under heat stress for 12 d, the activity of RuBPC quickly declined and the activity of PEPC first increased and later declined in all organs,...